I start my turn and another player casts sleep on me.

I have Reflection.

The sleep spell ends the character's turn.

If I use reflection on the person casting sleep, what happens to that character?

Will he miss his next turn, or has the spell been negated because it was my turn?

(I know there's been a thread about this concerning reflect on some spells, but I'm not 100% sure on this one)

The sleep spell is turned back onto the caster with no effect, due to the fact it is not his turn.